Chair Having A Synchronizing Mechanism

ABSTRACT

The invention relates to a seat comprising a lower frame which is placed on the floor ( 1 ) and on which a synchronous mechanism ( 2 ) is mounted. A horizontal fixed main rotational axle (D 1 ) and a horizontal secondary rotational axle (D 2 ) that can be pivoted about the main rotational axle (D 1 ) are arranged on the synchronous mechanism ( 2 ). Said synchronous mechanism ( 2 ) also comprises a fixed base ( 20 ) which is to be placed on the lower frame ( 1 ) and penetrated by the main rotational axle (D 1 ). A pivotable seat carrier ( 21 ) for fixing the seat element ( 3 ) is arranged above the base ( 20 ) and is penetrated by the secondary rotational axle (D 2 ). First connecting means ( 22 ) are fixed to the main rotational axle (D 1 ) and the secondary rotational axle (D 2 ) in an articulated manner. Second connecting means ( 23 ) are provided opposite the secondary rotational axle (D 2 ) as a connection between the base ( 20 ) and the seat carrier ( 21 ). A backrest ( 4 ) is fixed to the synchronous mechanism ( 2 ), said backrest being pivotable about the fixed main rotational axle (D 1 ) against the resistance of a spring module ( 24 ). The movements of the seat ( 3 ) and the backrest ( 4 ) are mutually synchronised.

APPLICATION AREA OF THE INVENTION

The present invention relates to a chair of the generic type having a substructure which is positioned on the floor and on which a synchronizing mechanism is mounted. The synchronizing mechanism has a fixed, horizontally running main rotary spindle and a horizontally running secondary rotary spindle which can be pivoted about the main rotary spindle. The synchronizing mechanism also has a fixed base which is intended for positioning on the substructure and through which the main rotary spindle runs. Arranged above the base is a pivotable seat carrier through which the secondary rotary spindle runs and on which a seat can be fastened. Articulated connecting means are provided between the main rotary spindle and the secondary rotary spindle. Further connecting means are provided opposite the secondary rotary spindle as a connection between the base and the seat carrier. A backrest is fastened on the synchronizing mechanism, which provides for synchronized movement between the seat and backrest, it being possible for the backrest to be pivoted about the fixed main rotary spindle counter to the resistance of a spring unit. The invention deals specifically with the compact construction and multiple functionality of the synchronizing mechanism within a chair designed therefor.

PRIOR ART

Synchronizing mechanisms, in particular for office chairs and other chairs for the workplace, have been used for many years now. The applicant therefore owns EP 0 592 369 B1, EP 0 839 478 B1, EP 1 039 815 B1 and EP 1 039 816 B1. A compact synchronizing mechanism has recently been proposed in EP 1 396 213.

OBJECT OF THE INVENTION

Based on the prior art which is already known in this respect, the object of the invention is to propose a chair of the generic type defined in the introduction which has an improved synchronizing mechanism, so that the basic construction is suitable for chairs of different configurations and levels or numbers of features. The intention is thus for mass production to be more efficient and, at the same time, for the functions to be further improved.

OVERVIEW OF THE INVENTION

The chair has, in the first instance, a substructure which is positioned on the floor and on which a synchronizing mechanism is mounted. The synchronizing mechanism has a fixed, horizontally running main rotary spindle and a horizontally running secondary rotary spindle which can be pivoted about the main rotary spindle. The synchronizing mechanism also comprises a fixed base which is intended for positioning on the substructure and through which the main rotary spindle extends. Arranged above the base is a pivotable seat carrier through which the secondary rotary spindle extends and on which a seat can be fastened. First connecting means are articulated, on the one hand, on the main rotary spindle and, on the other hand, on the secondary rotary spindle. Second connecting means are arranged opposite the secondary rotary spindle as a connection between the base and the seat carrier. A backrest is fastened on the synchronizing mechanism and can be pivoted about the fixed main rotary spindle counter to the resistance of a spring subassembly, the movements of the seat and backrest being synchronized in relation to one another. Characterizing is that the backrest having extensions which are fitted in a self-supporting manner on the first connecting means.

The following features relate to specific embodiments of the invention: Two extensions which are spaced apart parallel to one another, and each have a first and a second retaining contour, are provided on the backrest. The first retaining contours are fitted on the secondary rotary spindle and partially engage from beneath here around a respective spindle element of the first connecting means. The second retaining contours butt against the first connecting means.

In the state in which the backrest is inclined in the direction of the front seat edge, the first retaining contours on the extensions of the backrest can be fitted beneath the spindle elements of the first connecting means. As the backrest is pivoted back in the direction of the, in principle, vertical use position, the first retaining contours grip beneath the spindle elements in a claw-like manner, on the side which is directed toward the front seat edge, such that they slope upward from beneath. The second retaining contours are forced against the first connecting means by the torque generated by the weight of the backrest itself and the increase in this torque as the contact pressure against the backrest increases. The first connecting means are, in principle, two angle components, each angle component having the, in principle, cylindrical spindle element at the end which is associated with the secondary rotary spindle. A through-passage is present in the angle component, in front of the spindle element, and allows the first retaining contour to be fitted onto the spindle element. The second retaining contours on the extensions of the backrest are mating angles, each mating angle being supported on the associated angle component, engaging beneath the latter in the process. In order to secure the backrest fitted into the synchronizing mechanism, the second retaining contours on the extensions of the backrest are screwed on the angle components.

An accommodating connector for the adjustable insertion of a carrying arm, which is a constituent part of an armrest, is provided laterally on the synchronizing mechanism in each case. It is possible to change the depth to which the free end of the carrying arm is pushed into the accommodating connector, as a result of which it is possible to adjust the span between the two armrests provided on the chair. The accommodating connector is designed as a sleeve component of, in principle, rectangular inner cross section, and the free end of the carrying arm is in the form of a sliding component. The sliding component contains a slot through which projects the shank of a clamping screw which engages in the accommodating connector and serves for fixing the selected span of the armrests. The accommodating connectors extend from the seat carrier.

The spring subassembly in the synchronizing mechanism contains at least one mechanical spring and a pneumatic spring. The spring subassembly in the synchronizing mechanism advantageously comprises two helical springs and a pneumatic spring, the three springs being arranged in parallel. The pneumatic spring acts, in particular, as a damping member as the backrest is deflected into the rearwardly inclined position from its approximately vertical zero position. The prestressing generated by the spring subassembly can be set by means of an actuating member.

The synchronizing mechanism also has:

-   a) an arresting element for blocking the free synchronizing     movement; -   b) an actuating device for selecting in a stepwise manner the depth     to which the seat is extended in relation to the seat carrier; -   c) a device for setting a forward inclination of the seat carrier;     and -   d) on the base, a vertical opening for the insertion of the     outwardly extending outer tube of a height-specific pneumatic spring     positioned vertically in the substructure; and -   e) a guide track as second connecting means between the base and the     seat carrier, the seat carrier being displaced within the guide     track during the synchronizing movement.

A preferably elastic cover is provided for pulling over the backrest and as the essential constituent part of the latter, the cover being fixed in a releasable manner on a crossmember of the backrest by means of a cover holder. One end of the cover here is fastened on a base plate, which is arranged on the crossmember, while a second end of the cover is fastened on a latching plate, which can be fitted onto the base plate.

BRIEF DESCRIPTION OF THE ACCOMPANYING DRAWINGS

In the drawings:

FIG. 1A shows a front view of the chair according to the invention;

FIG. 1B shows a side view of the chair according to FIG. 1A;

FIG. 1C shows an exploded illustration of the chair according to FIG. 1A;

FIG. 2A shows an enlarged perspective illustration of a synchronizing mechanism from FIG. 1C (without the spring subassembly);

FIG. 2B shows an exploded illustration of the synchronizing mechanism according to FIG. 2A (with the spring subassembly);

FIG. 2C shows a plan view of the synchronizing mechanism according to FIG. 2A (with the spring subassembly);

FIG. 2D shows a perspective side view of the synchronizing mechanism according to FIG. 2C;

FIG. 2E shows a perspective side view from the rear of the synchronizing mechanism according to FIG. 2C;

FIG. 2F shows a perspective side view from beneath of the synchronizing mechanism according to FIG. 2C;

FIG. 3 shows a basic illustration of the seat-depth adjustments;

FIG. 4A shows a perspective view solely of a backrest with the extensions;

FIG. 4B shows a basic illustration of the initial phase of fitting the backrest on the synchronizing mechanism;

FIG. 4C shows a basic illustration of a backrest fully fitted on the synchronizing mechanism;

FIG. 5A shows a perspective illustration of an armrest having a carrying arm and sliding component, and also a clamping screw;

FIG. 5B shows a plan view of an armrest inserted in the accommodating connector;

FIG. 5C shows the perspective view from beneath of the armrest inserted in the accommodating connector, with the synchronizing mechanism as a whole;

FIG. 6A shows a basic illustration of a holder for the backrest cover; and

FIG. 6B shows a perspective illustration solely of the base plate and latching plate of a cover holder, in the separated state.

EXEMPLARY EMBODIMENT

A detailed description of an exemplary embodiment will be given hereinbelow, with reference to the accompanying drawings, in respect of the chair according to the invention.

The following applies to the rest of the description. If, in order to avoid ambiguity in the drawings, a figure contains designations which are not explained in the directly associated text of the description, then you are referred to the point at which they are mentioned in previous descriptions of the figures. For reasons of clarity, components are not usually designated again in subsequent figures, provided that it is clear from the drawings that they are “recurring” components.

The chair rests on a substructure 1 which is positioned on the floor and on which the synchronizing mechanism 2 is mounted. The fixed, horizontal main rotary spindle D1 and the horizontal secondary rotary spindle D2, which can be pivoted about the main rotary spindle D1, run through the synchronizing mechanism 2. The synchronizing mechanism 2 has:

-   -   a fixed base 20 which is intended for positioning on the         substructure 1 and through which the main rotary spindle D1         extends;     -   a seat carrier 21 which is arranged in a pivotable manner above         the base 20, through which the secondary rotary spindle D2         extends and on which a seat 3 can be fastened;     -   first connecting means 22 which are articulated, on the one         hand, on the main rotary spindle D1 and, on the other hand, on         the secondary rotary spindle D2; and     -   second connection means 23 which are arranged opposite the         secondary rotary spindle D2 as a connection between the base 20         and the seat carrier 21.

The backrest 4, which can be pivoted about the fixed main rotary spindle D1 counter to the resistance of a spring subassembly 24, is fastened on the synchronizing mechanism 2, the movements of the seat 3 and backrest 4 being synchronized in relation to one another. The backrest 4 has extensions 40 which are fitted in a self-supporting manner on the first connecting means 22. Two extensions 40 which are spaced apart parallel to one another, and each have a first and a second retaining contour 401,402, are provided on the backrest 4. The first retaining contours 401 are fitted on the secondary rotary spindle D2 and partially engage from beneath here around a respective spindle element 220 of the first connecting means 22. The second retaining contours 402 butt against the first connecting means 22.

In the state in which the backrest 4 is inclined in the direction of the front seat edge 30, the first retaining contours 401 on the extensions 40 of the bracket 4 can be fitted beneath the spindle elements 220 of the first connecting means 22. As the backrest 4 is pivoted back in the direction of the, in principle, vertical use position, the first retaining contours 401 grip beneath the spindle elements 220 in a claw-like manner, on the side which is directed toward the front seat edge 30, such that they slope upward from beneath. The second retaining contours 402 are forced against the first connecting means 22 by the torque generated by the weight of the backrest 4 itself and the increase in this torque as the contact pressure against the backrest 4 increases.

The first connecting means 22 are, in principle, two angle components 22, each angle component 22 having the, in principle, cylindrical spindle element 220 at the end which is associated with the secondary rotary spindle D2. A through-passage 221 is present in the angle component 22, in front of the spindle element 220, and allows the first retaining contour 401 to be fitted onto the spindle element 220. The second retaining contours 402 on the extensions 40 of the backrest 4 are mating angles 402, each mating angle 402 being supported on the associated angle component 22, engaging beneath the latter in the process. In order to secure the backrest 4 fitted into the synchronizing mechanism 2, the second retaining contours 402 on the extensions 40 of the backrest 4 are screwed on the angle components 22, preferably in the bottom region.

An accommodating connector 25 for the adjustable insertion of a carrying arm 50, which is a constituent part of an armrest 5, is provided laterally on the synchronizing mechanism 2 in each case. It is possible to change the depth to which the free end of the carrying arm 50 is pushed into the accommodating connector 25, as a result of which it is possible to adjust the span between the two armrests 5 provided on the chair. The accommodating connector 25 is designed as a sleeve component 25 of, in principle, rectangular inner cross section, and the free end of the carrying arm 50 is in the form of a sliding component 500. The sliding component 500 contains a slot 501 through which projects the shank 510 of a clamping screw 51 which engages in the accommodating connector 25 and serves for fixing the selected span of the armrests 5. The accommodating connectors 25 extend from the seat carrier 21. It is not necessary, in principle, for the clamping screw 51 to absorb any forces acting on the armrests 5 from above.

The spring subassembly 24 in the synchronizing mechanism 2 contains at least one mechanical spring 240 and a pneumatic spring 241. The spring subassembly 24 of the synchronizing mechanism 2 preferably contains two helical springs 240 and a pneumatic spring 241, the three springs 240,240,241 being arranged in parallel. The pneumatic spring 241 acts, in particular, as a damping member as the backrest 4 is deflected into the rearwardly inclined position from its approximately vertical zero position. The prestressing generated by the spring subassembly 24 can be set by means of the actuating member 242.

The synchronizing mechanism 2 also has:

-   -   an arresting element 26 for blocking the free synchronizing         movement;     -   an actuating device 27 for selecting in a stepwise manner the         depth to which the seat 3 is extended in relation to the seat         carrier 21, the actuating device comprising a lever with a         latching head and also a complementary latching grid on the         underside of the seat panel 31, above which the cushion panel 32         is arranged;     -   a device 28 for setting a forward inclination of the seat         carrier 21; and     -   on the base 20, a vertical opening 200 for the insertion of the         outwardly extending outer tube 100 of the height-specific         pneumatic spring 10 positioned vertically in substructure 1; and     -   a guide track 23 as a second connecting means 23 between the         base 20 and the seat carrier 21, the seat carrier 21 being         displaced within the guide track during the synchronizing         movement.

A preferably elastic cover 41 is provided for pulling over the backrest 4 and as the essential constituent part of the latter, the cover being fixed in a releasable manner on the crossmember 43 of the backrest 4 by means of a cover holder 42. One end of the cover is fastened on a base plate 420, which is arranged on the crossmember 43, and a second end of the cover is fastened on a latching plate 421, which can be fitted onto the base plate 420. The cover 41 can thus be removed relatively straightforwardly, e.g. for cleaning purposes. 

1. A chair having: a) a substructure (1) positioned on the floor, b) a synchronizing mechanism (2) which is positioned on the substructure (1) and has: ba) a fixed, horizontally running main rotary spindle (D1); bb) a horizontally running secondary rotary spindle (D2) which can be pivoted about the main rotary spindle (D1); bc) a fixed base (20) which is intended for positioning on the substructure (1) and through which the main rotary spindle (D1) extends; bd) a seat carrier (21) which is arranged in a pivotable manner above the base (20), through which the secondary rotary spindle (D2) extends and on which a seat (3) can be fastened; be) first connecting means (22) which are articulated, on the one hand, on the main rotary spindle (D1) and, on the other hand, on the secondary rotary spindle (D2); bf) second connecting means (23) which are arranged opposite the secondary rotary spindle (D2) as a connection between the base (20) and the seat carrier (21); c) a backrest (4) which is fastened on the synchronizing mechanism (2) and can be pivoted about the fixed main rotary spindle (D1) counter to the resistance of a spring subassembly (24), the movements of the seat (3) and backrest (4) being synchronized in relation to one another, characterized in that d) the backrest (4) has extensions (40) which are fitted in a self-supporting manner on the first connecting means (22).
 2. The chair as claimed in claim 1, characterized in that a) two extensions (40) which are spaced apart parallel to one another, and each have a first and a second retaining contour (401,402), are provided on the backrest (4); b) the first retaining contours (401) are fitted on the secondary rotary spindle (D2) and partially engage from beneath here around a respective spindle element (220) of the first connecting means (22); and c) the second retaining contours (402) butt against the first connecting means (22).
 3. The chair as claimed in at least one of claims 1 and 2, characterized in that a) in the state in which the backrest (4) is inclined in the direction of the front seat edge (30), the first retaining contours (401) on the extensions (40) of the backrest (4) can be fitted beneath the spindle elements (220) of the first connecting means (22); and b) as the backrest (4) is pivoted back in the direction of the, in principle, vertical use position: ba) the first retaining contours (401) grip beneath the spindle elements (220) in a claw-like manner, on the side which is directed toward the front seat edge (30), such that they slope upward from beneath; and bb) the second retaining contours (402) are forced against the first connecting means (22) by the torque generated by the weight of the backrest (4) itself and the increase in this torque as the contact pressure against the backrest (4) increases.
 4. The chair as claimed in at least one of claims 1 to 3, characterized in that a) the first connecting means (22) are, in principle, two angle components (22), each angle component (22) having the, in principle, cylindrical spindle elements (220) at the end which is associated with the secondary rotary spindle (D2); b) a through-passage (221) is present in the angle component (22), in front of the spindle element (220), and allows the first retaining contour (401) to be fitted onto the spindle element (220); and c) the second retaining contours (402) on the extensions (40) of the backrest (4) are mating angles (402), each mating angle (402) being supported on the associated angle component (22), engaging beneath the latter in the process.
 5. The chair as claimed in at least one of claims 1 to 4, characterized in that an accommodating connector (25) for the adjustable insertion of a carrying arm (50), which is a constituent part of an armrest (5), is provided laterally on the synchronizing mechanism (2) in each case.
 6. The chair as claimed in at least one of claims 1 to 5, characterized in that it is possible to change the depth to which the free end of the carrying arm (50) is pushed into the accommodating connector (25), as a result of which it is possible to adjust the span between the two armrests (5) provided on the chair.
 7. The chair as claimed in at least one of claims 1 to 6, characterized in that a) the accommodating connector (25) is designed as a sleeve component (25) of, in principle, rectangular inner cross section; b) the free end of the carrying arm (50) is in the form of a sliding component (500); c) the sliding component (500) contains a slot (501) through which projects the shank (510) of a clamping screw (51) which engages in the accommodating connector (25) and serves for fixing the selected span of the armrests (5); and d) the accommodating connectors (25) extend from the seat carrier (21).
 8. The chair as claimed in at least one of claims 1 to 7, characterized in that the spring subassembly (24) in the synchronizing mechanism (2) contains at least one mechanical spring (240) and a pneumatic spring (241).
 9. The chair as claimed in at least one of claims 1 to 8, characterized in that a) the spring subassembly (24) in the synchronizing mechanism (2) contains two helical springs (240) and a pneumatic spring (241), the three springs (240,240,241) being arranged in parallel; b) the pneumatic spring (241) acts, in particular, as a damping member as the backrest (4) is deflected into the rearwardly inclined position from its approximately vertical zero position; and c) the prestressing generated by the spring subassembly (24) can be set by means of an actuating member (242).
 10. The chair as claimed in at least one of claims 1 to 9, characterized in that the synchronizing mechanism (2) a) has an arresting element (26) for blocking the free synchronizing movement; b) has an actuating device (27) for selecting in a stepwise manner the depth to which the seat (3) is extended in relation to the seat carrier (21); c) has a device (28) for setting a forward inclination of the seat carrier (21); and d) on the base (20), contains vertical opening (200) for the insertion of the outwardly extending outer tube (100) of a height-specific pneumatic spring (10) positioned vertically in the substructure (1); and e) has a guide track (23) as second connecting means (23) between the base (20) and the seat carrier (21), the seat carrier (21) being displaced within the guide track during the synchronizing movement.
 11. The chair as claimed in at least one of claims 1 to 10, characterized in that, in order to secure a backrest (4) fitted into the synchronizing mechanism (2), the second retaining contours (402) on the extensions (40) of the backrest (4) are screwed on the angle components (22).
 12. The chair as claimed in at least one of claims 1 to 11, characterized in that a) a preferably elastic cover (41) is provided for pulling over the backrest (4) and as the essential constituent part of the latter, the cover being fixed in a releasable manner on a crossmember (43) of the backrest (4) by means of a cover holder (42); and b) one end of the cover is fastened on a base plate (420), which is arranged on the crossmember (43), and a second end of the cover is fastened on a latching plate (421), which can be fitted onto the base plate (420). 